Since they joined Major League Baseball in 1977, the Mariners have the most extra-inning grand slams in the game.
Kyle Seager hit a grand slam against the White Sox in extra innings on Wednesday, the 10th in franchise history.
After the Mariners, the Nationals/Expos have seven grand slams. The Padres, Cubs and Yankees have all hit six extra-inning grand slams since 1977.
Via Associated Press